BIO202H5 Lecture Notes - Lecture 8: Posterior Chamber Of Eyeball, Trachea, Partial Pressure
Document Summary
Air that is inhaled is moved right away (no valves, just pressure differences between chambers) from the trachea to air sacks. Compression of the chest moves the air in the posterior air sacks to the lungs where gas exchange occurs. Then, there is expansion of the chest and the air that has been exchanged leaves the bird. Blood flow is perpendicular to air flow (capillaries crossing blood vessels = crosscurrent exchange) Reciprocating (tidal) pattern, rather than flow through pattern of fluid. Less efficient because (cid:449)ith e(cid:448)er(cid:455) i(cid:374)halatio(cid:374), there"s a little (cid:271)it of re(cid:373)(cid:374)a(cid:374)t o(cid:454)(cid:455)ge(cid:374) that is(cid:374)"t used. We use the diaphragm to increase the volume of the thorax, which creates a pressure difference between the oxygen of the environment and the oxygen in the alveoli (where gas exchange occurs) The muscles that help us maximize and minimize the volume of the thorax are important, but so are those that protect the lungs.
